* {{cite book | last=Needham | first=Joseph | last2=Tsuen-Hsuin | first2=Tsien | title=Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology, Part 1, Paper and Printing | publisher=Cambridge University Press | publication-place=Cambridge | volume=5 | date=1985-07-11 | isbn=0-521-08690-6}}
<ref name="Needham Tsuen-Hsuin 1985 p. ">{{cite book | last=Needham | first=Joseph | last2=Tsuen-Hsuin | first2=Tsien | title=Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology, Part 1, Paper and Printing | publisher=Cambridge University Press | publication-place=Cambridge | volume=5 | date=1985-07-11 | isbn=0-521-08690-6 | page=}}</ref>